docs: def moveforum_view(self, request, forum_id, direction):
          """ Moves the given forum toward the requested direction. """
          forum = get_object_or_404(Forum, pk=forum_id)
  
          # Fetch the target
          target, position = None, None
          if direction == 'up':
              target, position = forum.get_previous_sibling(), 'left'
          elif direction == 'down':
              target, position = forum.get_next_sibling(), 'right'
  
          # Do the move
          try:
              assert target is not None
              forum.move_to(target, position)
          except (InvalidMove, AssertionError):
              pass
          self.message_user(request, _("'{}' forum successfully moved").format(forum.name))
          return HttpResponseRedirect(reverse('admin:forum_forum_changelist'))